Printing



y 1929- I A. L. GRAIQIME'R 1,711,596

PRINTING Filed March 18, 1927 //V VE 11/70 7 4 1 gramme EV I JTI'ORA EK.

Patented May '1, 1929.

UNITED STATES 1,711,596 PATEN OFFICE.

ALLEN L. GRAMMER, F GLENSIDE, PENNSYLVANIA.

PR NTING.

Application filed March 18, 1927. Serial No. 176,312.

Perfecting presses print on one side of a traveling web as it passesbetween a packing cylinder and one or more plate cylinders and thenprint on the other side of the web as it passes between another packingcylinder and its plate cylinder or cylinders with the freshly printedsurface next to the packing cylinder. The freshly printed surface at thesecond printing is exposed to the defect known as offset. Hitherto atympan or offset roll or sheet was fed through the second printingmechanism between the freshly printed side of the web and the top sheeton the packing cylinder to keep the ink from the freshly printed side ofthe web from offsetting to the top sheet on the packing cylinder whichwould in turn transfer the ink back to the paper web, marl-ing ordisfiguring the printing. The tympan or offset roll, which might becalled a sheet, feeds continuously with the paper web being printedpresenting a new surface with each impression until the end of theoffset or tympan roll is reached. In time, dependent upon the amount ofink used, the tympan or offset roll becomes covered with ink and must beremoved from the press. Among the difsheet at the same speed as the web,and if this is not done a part of the ink'is wiped or lifted, causingdistortion or blurring of the printed matter and reducing the usefullife of the tympan or offset sheet. The offset sheet is likely towrinkle and cause printing distortion and it frequently breaks, delayingthe printing operation. Again offset or tympan rolls or sheets vary inthickness throughout their lengths causing variation in impressionswhich deleteriously affect the quality of the printing. Again when theend of the tympan roll is-reached the press has to be stopped causingdelay. It is difficult to obtain clean printing when two colors areprinted on one side and four colors are printed on the second printingunit. The two colors first printed contact with the tympan or offsetsheet when the four color impressions are applied to the reverse side ofthe web causing what is known as four beats against the wet two colorimpression on the offset sheet, therefore four color printing backingfour color printing is not attempted.

Objects of the present invention are to eliminate the tympan or offsetsheet with its objections, among which some have been mentioned, and toprovide for preventing offset in a satisfactory, simple and bettermanner.

To these. and other ends the invention may be said to comprisesatisfactorily keeping the surface of the packing cylinder dampened, wetor moist with water which acts as an ink resist while at the same timekeeping the make-ready dry.

Theii invention also comprises the improvements to be presentlydescribed and finally claimed.

In the accompanying drawing there is illustrated one but not the onlymeans for practicing the invention and in the drawing Figure 1 is adiagrammatic View illustrative of perfecting presses, and

Fig. 2 is an enlarged diagrammatic View of a portion of the packingcylinder shown at the second printing mechanism in Fig. 1.

The method of the invention will be described in connection with theaccompanying drawing although its practice is not limited to themechanism thereshown.

In the drawing the packing cylinder 1 of the second printing unit isshown as provided with a smooth absorbent surface coat 2, and with anunderlying coat 3 of material adapted to prevent water or other inkresisting liquid absorbed by the coat 2 from reaching the make-ready. Ofcourse where the make-ready is not affected by water or moisture theimpervious sheet 3 may be omitted. An example of material well fittedfor use as the smooth, absorbent surface coat 2, but of course not theonly example, is cellophane which appears to be a cellulose compoundproduct that is smooth and readily absorbs water. 4 diagrammaticallyillustrates a means for supplying the surface of the packing cylinder 1with water. It is not the intention to limit the invention in all casesto the use of water but it is readily obtainable and therefore ismentioned as a fluid that is incompatible or does not mix with oils orvarnishes or inks or colors used in printing and usuallycontaining'either or both of those or like substances.

The paper web 5 in passing between the packing cylinder 6 and the platecylinders 7 and 8 is printed on one side, the righthand side in thedrawing, and in passing'between the packing cylinder 1 and the platecylink fications may be made in details of procedure ders 9 and 10 isprinted on the other, lefthand side in the drawing, and the freshlyprinted righthand side of the web is presented to the packingcylinder 1. The water, moisture or dampness on the surface of thepacking cylinder 1, however supplied, operating as an ink resist;opposes and prevents offset.

It will be obvious to those skilled in the art to which the inventionrelates that modiand in matters of mere form without departing from thespirit of the invention which is not limited to such matters orotherwisethan the prior art and the ap pended claims may require.

I claim:

1. The means of preventing ofiset at the freshly printed side of a paperweb traveling between a plate cylinder and the makeready of a packingcylinder with its freshly printed side toward the make-ready whichcomprise a smooth absorbent non-metallic surface provided on themake-ready, and

comprise a smooth absorbent non-metallic,

surface coat and an underlying coat impervious to water provided on themake-ready, and means for keeping said absorbent surface coat wet withwater.

3. The means of preventing offset at the freshly printed side of a paperweb traveling between'a plate cylinder and the makeready of a packingcylinder with its freshly printed side toward the make-ready whichcomprise a coat of a cellulose compound product and an underlying coatimpervious to water provided on the make-ready, and 'means for keepingsaid absorbent. surface coat wet with water.

ALLEN L. GRAMMER.

